The Telegraph - Calcutta : Frontpage

The Telegraph - Calcutta : Frontpage

Earth’s cousin, wet and warm
G.S. MUDUR

An artist’s impression shows Earth (left), the new planet and the red dwarf star Gliese 581
New Delhi, April 25: Astronomers have discovered the first planet outside the solar system that could have liquid water and liveable temperatures, a potential new spot to look for extraterrestrial life.

The “most Earth-like planet yet”, orbiting a red dwarf star named Gliese 581, is the first that appears to lie in a habitable zone — the region around a star where water is in its liquid form — a team of European astronomers said.

The astronomers who announced their finding today in the journal Astronomy and Astrophysics, have estimated that the average temperature on the planet — which is about five times more massive than the Earth — would be 0 to 40 degrees Celsius.

Like other exoplanets — planets orbiting other stars — the planet around Gliese 581 is too small and too far for direct observations or temperature measurements.

“This planet will most probably be a very important target of future space missions dedicated to the search for extraterrestrial life,” said Xavier Delfosse, a team member at Grenoble University in France. “On the treasure map of the universe, one would be tempted to mark this planet with an X,” Delfosse said.

Gliese 581 is among the 100 stars closest to the solar system — only 20 light years away from the Sun, but smaller and colder.

Smaller planets are harder to find, but computer simulations show that they are more likely to hold water. “Calculations show that small planets turn out to be rocky like Mars or Earth,” Xavier Bonfils, a team member at Lisbon University, Portugal, told The Telegraph.

“During formation, small planets may accumulate water which — if still present — would be liquid in the temperature range we’ve estimated.”

The scientists detected the Super Earth by observing the change in the velocity of the parent star typically caused by orbiting planets.

They used an instrument called HARPS located in an observatory perched high in the mountains of Chile.